This is not only really cool, but it has striking implications for makers of film and TV. Using a technology called Eyelink, which uses an infrared camera to track the movement of a viewer’s pupil once every millisecond, film theorists analyzed how a test group of eleven viewers watched scenes from various films. The results revealed some very interesting bits of data: first, just how quickly our eyes move around the screen, even while we’re watching a scene that’s fairly static — about once every 1/3rd second. Another interesting finding was just how synchronized the roving gaze of eleven viewers actually was — in a phenomenon they call attentional synchrony, something about movement in a scene leads to all viewers looking at the same place on the screen at the same time.

They use the following scene from There Will Be Blood as an example. There are only a few cuts; it’s mostly long master takes, which makes it easy to see how changes in the scene itself, rather than edits, re-direct viewers’ attention. It’s hypnotizing and slightly surreal to watch a scene along with the eyeballs of eleven other people.

So what can we take away from all this? If you happen to be a filmmaker, plenty: mainly that there are lots of effective and satisfying ways to direct and manipulate the gaze of an audience member other than close-ups, reverse shots, etc. You can do all of that in a single shot, by moving the actors rather than the camera. David Bordwell analyzes the attentional synchrony of the scene beat-by-beat in this article, but here’s the takeaway:

Viewers’ gazes are attracted by the sudden appearance of objects, moving hands, heads, and bodies. The greater the motion contrast between the point of motion and the static background, the more likely viewers will look at it. If there is only one point of motion at a particular moment, then all viewers will look at the motion, creating attentional synchrony.

By minimising background distractions and staging the scene in a clear sequential manner using basic principles of visual attention, P. T. Anderson has created a scene which commands viewer attention as precisely as a rapidly edited sequence of close-up shots. The benefit of using a single long shot is the illusion of volition. Viewers think they are free to look where they want but, due to the subtle influence of the director and actors, where they want to look is also where the director wants them to look. A single static long shot also creates a sense of space, clear relationship between the characters, and a calm, slow pace which is critical for the rest of the film. The same scene edited into close-ups would have left the viewer with a completely different interpretation of the scene.